Njxs richard



Oct. 30 1923.

N. FORSSBLAD ELECTRIC STEAM AND HOT WATER BOILER Original Filed June' 101920 i. a a 7 M Reissued on. so, 1923.

UNITED STATES PATEN OFFICE.

I ILS RICHARD, FOBSSBLAD, OI VA BTEBLS, SWEDEN.

ELIXITBIC STEAK AND HOT-WATER BOILER.

Original 80. 1,380,487, dated August 2, 1921, Serial Io. 888,082, medJune. 10, 1820. Application for reissue filed August 29, 1922. SerialRe. 585,050.

To all whom it may concern Be it known that I, NILs RICHARD Fonssnmn, asub'ect of the King of Sweden, re siding at asteras, Sweden, haveinvented 8 certain new and useful Improvements in Electric Steam andHot-Water Boilers, of which the following is a specification;

The present invention relates to such steam or hot water boilersin whichthe steam is produced by an electrical current passin directly betweenelectrodes sub mer in the water.

In all boilers of the type herein considered the electrodes will have tobe sur- 1 rounded by tubes of some insulating material in order toprevent direct short circuits between the electrodes. The control of theoutput, which is generally wanted, was heretofore obtained mostly bydisconnecting 80 one or more electrodes by means of a plurality ofswitches arranged outside the boil- According to the present inventionthe control of the output is effected by raising 2B or lowerin theinsulating tubes surrounding the electr es, whereby the length andthereby the resistance of the water columns within the tubes is varied.By'this arrangement the output of the boiler may thus be varied withincertain limits, without changing the number of electrodes connected incircuit. Therefore, the number of electrodes answering certainrequirements for control need not be as large as in the constructionsheretofore employed, and this, evidentsimilar longitudinal and crosssections respectively.

The shell of the boiler is designated by 1. The numeral 2 denotes theelectrodes, 3 the inlet ducts, 4 the insulating tubes and 5 acontrivance for keeping these tubes together. 6 are ropes by means ofwhich the tubes may be raised and 7 is ahoisting device for .the ropes,such device consisting of a rotatable shaft, and operatin means in theform of a hand wheel. rrangements other than the one herein disclosedmay obviously be used for raising and lowering the pipes 4, sucharrangements comprising, for example, devices operated by tooth racks orlevers.

Themode of operation of the boiler is as follows: the electricalcurrent, preferably a. multiphase alternating current, is led into theboiler at the lower side thereof through the inlet ducts 3 and to theelectrodes 2, and the current then passes through the water between theelectrodes. According as the tubes 4 are raised or lowered by means ofthe ropes 6 and the shaft 7, the resistance of the water between theelectrodes varies, and consequently also the output of the boilorvaries.

The electrodes may be of an form suitable for the purpose but pre erablythey are ball-shaped. Generally, they should have a relatively shortlength inthe longi tudinal direction of the surrounding tu The tubes arepreferably open at both ends, so as to allow of a free circulation ofthe water and to allow the circuit to be closed in both directionsthrough the tube. .The same arrangements for control may evidently beused also in boilers employed only for the purpose of heating water.

I claim as my invention:

1. In an electrical steam or hot-water boiler, a number of submergedelectrodes introduced through the bottom of the boiler, and a suhmer edinsulating tube surrounding each of said electrodes, said tube beingopen at both ends.

2. In an electrical steam or hot-water boil- Q i I 13,110

er the combination of a number of submerged electrodes introducedthrough the er, the combination of a plurality of'sub-, to, bottom ofthe boiler, a. submer d insulatmerged electrodes introduced through the"ing tube surrounding each -o said elecbottom of the boiler and a submerd inl trodes, said tube being in open communicasulating tube surroundingeach of said election with the waterat both ends, and means trodes,'said tube being in open communicafor displacing the tubes in alongitudinal tion with the water at both ends.

direction. NILS RICHARD FORSSBLAD.

3. In an electrical steam or hot water boil-

